An automotive seat belt device comprises a belt buckle for fastening a belt, and the belt buckle is typically configured to detachably retain thereto a tongue piece connected to an end of the belt. See Japanese patent laid open publication No. 6-239201 (patent document 1). According to the known seat belt device, when fastening the belt, the user is required to hold the tongue piece and buckle by two hands, respectively, and insert the tongue piece into an opening of the buckle. If the buckle is clearly visible to the user and fixed in position, the seat belt may be fastening by using one hand, but there may be some difficulty in properly positioning the tongue piece with respect to the opening of the buckle particularly when the user is unable to see the buckle from a proper viewing angle.
Such belt buckle devices are also used for other applications such as securing various members on the body of a user. Such members, not exclusively, include footwear, protective gears and frame members for assisting a handicapped person.